Seleção de genitores e potencial de populações segregantes de trigo
Data
2022-02-21
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Editor
Universidade Federal de Viçosa
Resumo
A adequada seleção de genitores superiores e complementares para composição de blocos de cruzamento e formação de populações base promissoras para a prática de seleção é uma etapa determinante no sucesso dos programas de melhoramento de trigo. Os objetivos com este trabalho consistiram em selecionar genitores de trigo tropical com maior frequência de alelos favoráveis e populações segregantes com maior potencial para originar progênies superiores através da análise dialélica parcial. Para este propósito, 14 genitores foram divididos em dois grupos e cruzados em esquema de dialelo parcial 7 × 7 para originar 49 combinações F 1 . Após a obtenção da geração F 2 , as populações, juntamente com os genitores e uma cultivar comercial, foram avaliadas a campo no delineamento látice 8 × 8, com duas repetições, em dois experimentos conduzidos entre os meses de junho a outubro de 2021. As características avaliadas foram espigamento, altura de plantas, resistência a ferrugem e mancha amarela, massa de espiga, comprimento de espiga, número de espiguetas por espiga, número de grãos por espiga, massa de grãos por espiga, massa de cem grãos e produção de grãos por parcela. Os dados foram submetidos às análises de variância individual e conjunta. As médias das populações foram comparadas com as médias de dois genitores pelo teste de Dunnet. Por fim, realizou-se a análise dialélica parcial conjunta. Houve significância dos efeitos médios de capacidade geral de combinação dos grupos I e II para todas as características (exceto massa de cem grãos). O efeito médio de capacidade específica de combinação, foi significativo para espigamento e altura de planta. Houve significância da interação capacidade geral de combinação do grupo I × ambiente para altura de planta, comprimento de espiga, mancha amarela, massa de cem grãos e produção de grãos. Houve significância da interação capacidade geral de combinação do grupo II × ambiente para espigamento e massa de cem grãos. A interação capacidade específica de combinação × ambiente foi significativa para mancha amarela, massa de cem grãos e produção de grãos. Os efeitos gênicos aditivos foram superiores em relação aos não aditivos. Foram selecionados em cada grupo os genitores com maior frequência de alelos favoráveis para ciclo curto, baixa altura de plantas, resistência a doença e componente de rendimento. Para produção de grãos, um genitor foi selecionado. Quatro populações com elevado potencial genético para originar progênies superiores foram selecionadas. Palavras-chave: Triticum aestivum L. Dialelo Parcial. Capacidade Geral de Combinação. Capacidade Específica de Combinação. Interação Genótipo × Ambiente.
The adequate selection of superior and complementary parents for the composition of crossing blocks and formation of promising base populations for the practice of selection is a determining step for the success of wheat breeding programs. The goals with this work were select tropical wheat parents with the highest favorable allele frequency and populations with the highest genetic potential to originate superior progenies through partial diallel analysis. Thus, 14 parents were divided in two groups and crossed on a 7 × 7 partial diallel mating design to originate 49 F 1 combinations. After obtaining the F 2 generation, the parents, populations and one commercial cultivar were evaluated in the field on an 8 × 8 lattice design, in two replications and two environments between June and October, 2021. The traits evaluated were days for heading, plant height, resistance to leaf rust and tan spot, spike mass, spike length, number of spikelets per spike, number of grains per spike, grain mass per spike, hundred grain mass and grain yield. The data were subjected to individual and joint analysis of variance. The means of the populations were compared with the means of two parents by the Dunnet test. Joint partial diallel analysis was performed. There was significance of the mean effects of general combining ability from groups I and II for all the traits (except for hundred grain mass). The mean effect of specific combining ability was significative for days for heading and plant height. There was significance of the interaction general combining ability of group I × environment for plant height, spike length, tan spot, hundred grain mass and grain yield. There was significance of the interaction general combining ability of group II × environment for days for heading and hundred grain mass. The interaction specific combining ability × environment was significative for tan spot, hundred grain mass and grain yield. The additive genetic effects were superior compared to non-additive. Were selected, in each group, the parents with the highest favorable allele frequency for early cycle, low plant height, disease resistance and yield components. For grain yield, one parent was selected. Four populations with high genetic potential to originate superior progenies were selected.Keywords: Triticum aestivum L. Partial Diallel. General Combining Ability. Specific Combining Ability. Genotype × Environment Interaction.
The adequate selection of superior and complementary parents for the composition of crossing blocks and formation of promising base populations for the practice of selection is a determining step for the success of wheat breeding programs. The goals with this work were select tropical wheat parents with the highest favorable allele frequency and populations with the highest genetic potential to originate superior progenies through partial diallel analysis. Thus, 14 parents were divided in two groups and crossed on a 7 × 7 partial diallel mating design to originate 49 F 1 combinations. After obtaining the F 2 generation, the parents, populations and one commercial cultivar were evaluated in the field on an 8 × 8 lattice design, in two replications and two environments between June and October, 2021. The traits evaluated were days for heading, plant height, resistance to leaf rust and tan spot, spike mass, spike length, number of spikelets per spike, number of grains per spike, grain mass per spike, hundred grain mass and grain yield. The data were subjected to individual and joint analysis of variance. The means of the populations were compared with the means of two parents by the Dunnet test. Joint partial diallel analysis was performed. There was significance of the mean effects of general combining ability from groups I and II for all the traits (except for hundred grain mass). The mean effect of specific combining ability was significative for days for heading and plant height. There was significance of the interaction general combining ability of group I × environment for plant height, spike length, tan spot, hundred grain mass and grain yield. There was significance of the interaction general combining ability of group II × environment for days for heading and hundred grain mass. The interaction specific combining ability × environment was significative for tan spot, hundred grain mass and grain yield. The additive genetic effects were superior compared to non-additive. Were selected, in each group, the parents with the highest favorable allele frequency for early cycle, low plant height, disease resistance and yield components. For grain yield, one parent was selected. Four populations with high genetic potential to originate superior progenies were selected.Keywords: Triticum aestivum L. Partial Diallel. General Combining Ability. Specific Combining Ability. Genotype × Environment Interaction.
Descrição
Palavras-chave
Triticum aestivum - Genética, Recombinação - Genética, Interação genótipo - ambiente
Citação
SILVA, Caique Machado e. Seleção de genitores e potencial de populações segregantes de trigo. 2022. 67 f. Dissertação (Mestrado em Genética e Melhoramento) - Universidade Federal de Viçosa, Viçosa. 2022.